1. Field of the Invention
The present invention relates to a process for making rubber tracks and to a rubber track made thereby.
The concerned tracks consist of a rubber strip comprising an inextensible core made up of longitudinally disposed steel wires, and of a series of strengthening steel insert pieces positioned at locations where tracks rest on the ground. The steel wires and insert pieces are buried into the rubber strip externally exhibiting suitably shaped ridges (as well as on the inner side thereof), depending upon the requirements of use and the type of ground on which the track-laying vehicle must work.
2. Prior Art
Presently, in accordance with the known art, the production of rubber tracks involves the use of a rectilinear rubber strip having a predetermined length and containing one or, more often, two series of steel wires which are disposed inside the strip in coplanar relation with the strip itself on either side of the central area thereof. The steel wires are in the form of cut-down sizes the length of which corresponds to the length of the rubber strip, and are disposed parallelly to one another.
In order to make the track acquire a ring shape, the rubber strip is bent and the two strip ends are overlapped over a certain length thereof. Such ends are then joined by means of an adhesive and by molding vulcanization. The ends of the steel wires therefore are not welded together but are only overlapped, buried into the rubber strip in the junction area of the latter.
As a result, in the junction area the rubber strip becomes thicker and therefore its profile appears uneven, which brings about two main drawbacks.
First of all, during the passage onto the track's toothed wheel said junction area behaves stiffly and consequently the homogeneity of movement is reduced.
In addition, at the point where there is a variation in the track section, the material exhibits a change in strength. It is known, in fact, that the areas concerned with a section variation constitute critical fatigue points where the material is preferably more subjected to stress decay.